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Need Help Understanding Audio Resolution


Youthman

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Currently in my 2ch setup, I have a Harman Kardon HK3490 receiver (used as a preamp) connected to an Acurus A200 (200 x 2) amp powering a pair of Klipsch RF-7 II speakers. I listen to Spotify by streaming it to the system via an Apple Airport Express. The Airport Express has a 3.5mm connection so I have always used a 3.5mm to RCA cable. I recently was told that I could use a Toslink cable which would allow me to use the DAC in the HK vs the inferior DAC in the Airport Express.

 

After looking at images online, it does appear that the Airport Express accepts Analog or Digital Input via the same input. Here is the cable I purchased https://www.amazon.com/…/B00…/ref=oh_aui_detailpage_o03_s00…. I didn't know they made such a cable. I have only seen the larger square toslink connections on both ends of the cable. About to test it out to see if I can hear a difference.

 

61oyWAGm4uL._SL1000_.jpg

 

As you can see, the Airport Express has an Analog / Optical Audio Jack

 

MC414_AV3_GEO_US?wid=1000&hei=1000&fmt=j

 

Someone on Facebook said " fyi, that toslink port is limited to 44.1/16." but looking at the Deezer HiFi link that another guy posted, they make it sound like 44.1/16 is lossless so how would that be considered "limited"?

 

Here is a quote from their page.

"When a song is compressed for MP3s or
streaming, an algorithm removes bits from it to make the file smaller. Regular streaming and MP3s stream at 320kbps, which is enough for your ears to understand the song, but HiFi streams at 16-Bit / 44.1 kHz of FLAC quality, so you can hear all the bits that existed with the original analog audio sources. It's like putting your glasses on, but for your ears."

 

So all of that to say this....is my Airport Express bottle necking my Spotify Premium set to Extreme Quality which streams at 320 kbps?  If so, what other streaming options could I connect my iPhone 6 to that would allow me to stream the highest possible with it?

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9 minutes ago, Youthman said:

After reading through this article...(snip!)

I read the article just now.  The many formats and accompanying solutions boggle the mind.  

 

It seems crazy to have all the top notch speakers and amps many people do then have to compromise on the source material.

 

 

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9 hours ago, Youthman said:

maybe there isn't a good solution to stream really high resolution from my iPhone to my 2ch system.

Look at the specs on your iPhone and see if it mentions high resolution audio.

 

My HTC One M8 specs state that it supports up to 24/192 streaming audio.  Not sure if it down samples when streaming via Chromecast Audio.  I know it will stream high rez to my Oppo 105.

 

Bill

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It is my understanding that the Apple Express will down sample all formats to 16/44 as that is the maximum resolution that it will stream. I was using an Apple TV box to stream via AirPlay and this was the case. I spent a lot of time researching this. I bought an Audioengine D2 streamer which streams all music at 24/96 on a dedicated wifi network. The sound is outstanding and the link is very reliable. 

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So

14 hours ago, willland said:

Look at the specs on your iPhone and see if it mentions high resolution audio.

From what I'm reading online, it's limited (not sure the exact specs)

 

15 minutes ago, Derrick said:

I bought an Audioengine D2 streamer which streams all music at 24/96 on a dedicated wifi network. The sound is outstanding and the link is very reliable. 

So would I be able to stream from my iPhone to the D2 through my wireless home network at 24/96?

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Looks like the D2 needs to be connected to a computer.  Not what I'm looking for since the computer is in the Home Office and would not be convenient to use when the 2ch is setup in my living room.  Pricey little booger too.  LOL

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So your Airport Express is your wireless conduit right?  It does have digital toslink out correct?  You send music from your iPhone to your AE and then to DAC and then to HK.

On 10/7/2017 at 10:37 PM, Youthman said:

After looking at images online, it does appear that the Airport Express accepts Analog or Digital Input via the same input.

The analog/optical jack is an output not an input.

https://www.cnet.com/news/using-apples-airport-express-with-a-dac-a-how-to-guide/

 

Bill

 

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7 hours ago, Youthman said:

Looks like the D2 needs to be connected to a computer.  Not what I'm looking for since the computer is in the Home Office and would not be convenient to use when the 2ch is setup in my living room.  Pricey little booger too.  LOL

 

https://tampa.craigslist.org/pnl/ele/d/cambridge-audio-dac-magic-100/6328217401.html

 

https://tampa.craigslist.org/pnl/ele/d/maverick-audio-d1-digital-to/6323710251.html

 

https://www.mav-audio.com/store/index.php/dac/tube-magic-dac-d1-1.html

 

https://fortmyers.craigslist.org/chl/sop/d/audioengine-d1-24-bit-dac/6334422037.html

 

Bill

 

 

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On 10/7/2017 at 9:37 PM, Youthman said:

 

 

So all of that to say this....is my Airport Express bottle necking my Spotify Premium set to Extreme Quality which streams at 320 kbps?  If so, what other streaming options could I connect my iPhone 6 to that would allow me to stream the highest possible with it?

The answer is no, Airplay and your AE are not the bottleneck here - they stream at 16/44.1 compressed lossless (Apple calls this ALAC) which is CD quality.  This is also the limit of your iPhone.  Pretty darn good to my ears if I may say so.  Hook up your AE via Toslink optical to your HK and you should hear a nice improvement.

 

The weak link in this chain is Spotify Premium (MP3 320) and probably the files stored on your iPhone are AAC-256 format, the standard for the iTunes store.  Both MP3 and AAC are compressed lossy formats.  When the Spotify app on your iPhone streams MP3 or the Music app plays an AAC file out via Airplay to your AE, Airplay actually rehydrates it to 16/44.1 ALAC.  But, as others have pointed out, there is no getting back the missing bits that were discarded when the music was saved as MP3/AAC.  You can save music in 16/44.1 ALAC format (from CD rips or HDTRACKS for example) to your iPhone for maximum quality (matching what Airplay is capable of) at the expense of chewing through disk space on your iPhone.  

 

There is no point in looking at higher-resolution streaming solutions if your sources are all compressed and lossy.  Save your money.

 

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Thanks for the follow up.  I've been super busy developing a 50 page website for a new client and preached a wedding last night but I was able to briefly demo and wasn't sure I was able to hear a difference between the two.  I guess I thought it was going to be a "WOW moment".  Today should be pretty laid back so I'll see if I can do a few more A/B comparisons and will post back.

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The DAC inside the AE is surprisingly decent.  Some generations of AE have a better reputation than others too.  With today's advanced digital technology, I don't think there is ever a "wow" moment swapping around DACs - more like 'subtle differences' due to one integrating into your system slightly better than the other.  At least this has been my experience in the sub-$600-ish range of DACs.

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It was mentioned that the HK DAC should sound significantly better then the AE DAC but I’m just not hearing it.  Both sound good.  Can’t describe any differences I’m hearing if any at all.  Maybe my hearing just sucks.  LOL

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2 hours ago, Youthman said:

It was mentioned that the HK DAC should sound significantly better then the AE DAC but I’m just not hearing it.  Both sound good.  Can’t describe any differences I’m hearing if any at all.  Maybe my hearing just sucks.  LOL

I found some specs from the two DACs used in both your Airport Express(PCM2705) and your HK3490(AK4589).

 

I know specs don't mean everything.
 

 

Image result for PCM2705 specs

AK4589 001.jpg

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6 hours ago, Youthman said:

It was mentioned that the HK DAC should sound significantly better then the AE DAC but I’m just not hearing it.  Both sound good.  Can’t describe any differences I’m hearing if any at all.  Maybe my hearing just sucks.  LOL

That's possible!  My hearing is 48 years old and most things this age don't work as well as they once did.  It could also be your HK is doing some additional DSP in the chain that sort of nullifies any small differences in the DAC.  Regardless, I think differences in DACs are pretty fair down the chain in terms of making an audible "wow factor."

 

I just ran a test since it is a rainy Saturday up here in Chicago.  I recruited my daughter for 10 minutes - she's got 16 year old hearing and a classically trained ear from playing the viola.  I played the first 30 seconds of a well recorded hi-res track several times.  Path A was Airplay --> AE --> Schiit Bifrost 4490 DAC --> McIntosh MA6500 --> H3.  Path B eliminated the Schiit.  She asked me to switch several times A B A, then A and B.  It was close with subtle differences.  However she did prefer Path A (Schiit)- more open, natural, with distinct separation of instruments against a black background.  The AE was good but the vocals were more front-and-center with the instruments more bunched up behind the vocals.  I could hear the difference too BTW but I just wanted to make sure it wasn't a placebo, and my daughter acted as the neutral referee.

 

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19 hours ago, Youthman said:

@willland are there any specs that stand out to you?

Well it looks like the PCM2705(AE) has a SNR of 98dB with a dynamic range also at 98dB.  The AK4589(HK) on the other hand has a SNR of 92dB with a dynamic range of 102dB for the ADC stereo portion and the 8 channel DAC portion has a SNR of 94dB with a dynamic range of 114dB.  On paper, the HK's built in DAC and ADC should provide better sonics mainly because of the dynamic range, even though it has a higher noise floor.  The Airport Express looks to be highly compressed with no dynamic range at all.  

 

I am not completely versed in all of this stuff but I think I explained it well enough for people to at least think I know what I am talking about.:o;):P

 

Bill

 

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